//定义懒加载插件
import { useIntersectionObserver } from '@vueuse/core'
import { install } from 'element-plus'

export const lazyPlugin = {
  install (app) {
    //懒加载指令逻辑
    app.directive('img-lazy' , {
      mounted(el,binding) {
        //el:指令绑定的那个元素：img
        //binding:binding.value 指令等于号后面绑定的表达式的值 图片url
        console.log(el, binding.value)
        useIntersectionObserver(
          el,
          ([{ isIntersecting }]) => {
            console.log(isIntersecting)
            if(isIntersecting){
              //进入视图区域
              el.src = binding.value
              stop()
            }
          }
        )
      }
    })
  }
}
